The present disclosure relates to spectroscopy, and more particularly to transmission Raman spectroscopy. There are many situations in which a sample is presented, the contents of which are unknown. It may not be immediately obvious what substances are contained in the sample. For example, one may not be able to tell what substances the sample contains by simply looking at the sample, or the like, especially if the sample is within a container. Moreover, it may not be immediately obvious if the sample contains impurities, illicit and/or dangerous substances, substances of interest, or the like.